Extracts of fetal calf-skin collagen contains several collagenous proteins including a previously-reported type III procollagen, a higher molecular-weight protein (HMWP) and a very-high molecular-weight protein (VHMWP) as judged by SDS-acrylamide gel electrophoresis. We have purified both the procollagen of Byers et al. and the HMWP on DEAE-cellulose columns. The VHMWP appears to be a precursor of HMWP and collagen. Unlike the procollagen of Byers et al., HMWP is not digested by collagenase although it has a similar amino acid composition. Thus, VHMWP and HMWP appear to be novel forms of procollagen.